1. Field of the Invention
The present invention relates to an array substrate that can be used in an active matrix display.
2. Description of the Related Art
U.S. Pat. No. 6,373,454 describes an active matrix organic electroluminescent (EL) display in which each pixel circuit utilizes a current mirror circuit. The pixel circuit includes an n-channel field-effect transistor as a drive transistor, an organic EL element, a capacitor, an output control switch, a selector switch, and a diode-connecting switch.
The source of the drive transistor is connected to a first power supply line at a low potential. The capacitor is connected between the gate of the drive transistor and the first power supply line. The output control switch is connected between the drain of the drive transistor and the cathode of the organic EL element. The anode of the organic EL element is connected to a second power supply line at a higher potential. The selector switch is connected between the drain of the drive transistor and a video signal line. The diode-connecting switch is connected between the drain and gate of the drive transistor. Each of the switches is normally composed of a field-effect transistor.
As typified by the above circuit, each pixel circuit in an active matrix organic EL display includes an organic EL element and a field-effect transistor. In the manufacture of such an organic EL display, the field-effect transistor may suffer electrostatic damage after a pixel electrode is formed and before the organic EL element is completed. The electrostatic damage to the field-effect transistor in a pixel may cause the pixel to be viewed as a luminous dot or a dark dot.